PTOLEMY II - CiteSeerX

More documents

Recommendations

Info

Using Vergil The “free” in these expressions refers to the mode refinement in the free state. Thus, free.initialPosition is a parameter of that mode refinement. Here, its value is assigned to the value of the parameter initialPosition. The parameter free.initialVelocity is set to zero. The reset parameter is set to true, meaning that the destination mode refinement will be initialized when the transition is taken. The preemptive parameter is set to false. In this case, it makes no difference, since the init state has no refinement. Normally, if a transition out of a state is enabled and preemptive is true, then the transition will be taken without first executing the refinement. Thus, the refinement will not affect the outputs of the modal model. A state may have several outgoing transitions. However, it is up to the model builder to ensure that at no time does more than one guard on these transitions evaluate to true. In other words, Ptolemy <strong>II</strong> does not allow nondeterministic state machines, and will throw an exception if it encounters one. Creating Refinements. Both states and transitions can have refinements. To create a refinement, right click 1 on the state or transition, and select “Add Refinement.” You will see a dialog like that in figure 2.62. As shown in the figure, you will be offered the alternatives of a “Default Refinement” or a “State Machine Refinement.” The first of these provides a block diagram model as the refinement. The second provides another finite state machine as the refinement. In the former case (the default), a blank refinement model will open, as shown in the figure. As before, the output port will appear in an inconvenient location. You will almost certainly want to move it to a more convenient location. You will have to create a director in the refinement. The modal model will not operate without a director in the refinement. You can also create refinements for transitions, but these have somewhat different behavior. They will execute exactly once when the transition is taken. For this reason, only certain directors make sense in such refinements. The most commonly useful is the SDF director. Such refinements are typically used to perform arithmetic computations that are too elaborate to be conveniently specified as an action on the transition. FIGURE 2.62. Adding a refinement to a state. 1. On a Macintosh, control-click. output port 88 Ptolemy <strong>II</strong>
Using Vergil Once you have created a refinement, you can look inside a state or transition. For the bouncing ball example, the refinement of the free state is shown in figure 2.58. This model exhibits certain key properties of refinements: Refinements must contain directors. In this case, the CTEmbeddedDirector is used. When a continuous-time model is used inside a mode, this director must be used instead of the default CTDirector (see the CT domain documentation for details). The refinement has the same ports as the modal model, and can read input value and specify output values. When the state machine is in the state of which this is the refinement, this model will be executed to read the inputs and produce the outputs. 2.10.4 Execution Semantics The behavior of a refinement is simple. When the modal model is executed, the following sequence of events occurs: For any transitions out of the current state for which preemptive is true, the guard is evaluated. If exactly one such guard evaluates to true, then that transition is chosen. The output actions of the transition are executed, and the refinements of the transition (if any) are executed, followed by the set actions. If no preemptive transition evaluated to true, then the refinement of the current state, if there is one, is evaluated at the current time step. Once the refinement has been evaluated (and it has possibly updated its output values), the guard expressions on all the outgoing transitions of the current state are evaluated. If none is true, the execution is complete. If one is true, then that transition is taken. If more than one is true, then an exception is thrown (the state machine is nondeterministic). What it means for the transition to be “taken” is that its output actions are executed, its refinements (if any) are executed, and its set actions are executed. If reset is true on a transition that is taken, then the refinement of the destination mode (if there is one) is initialized. There is a subtle distinction between the output actions and the set actions. The intent of these two fields on the transition is that output actions are used to define the values of output ports, while set actions are used to define state variables in the refinements of the destination modes. The reason that these two actions are separated is that while solving a continuous-time system of equations, the solver may speculatively execute models at certain time steps before it is sure what the next time step will be. The output actions make no permanent changes to the state of the system, and hence can be executed during this speculative phase. The set actions, however, make permanent changes to the state variables of the destination refinements, and hence are not executed during the speculative phase. 2.11 Using the Plotter Several of the plots shown above have flaws that can be fixed using the features of the plotter. For instance, the plot shown in figure 2.49 has the default (uninformative) title, the axes are not labeled, and the horizontal axis ranges from 0 to 2551 , because in one iteration, the Spectrum actor produces 256 output tokens. These outputs represent frequency bins that range between – π and π radians per second. 1. Hint: Notice the “x10 2 ” at the bottom right, which indicates that the label “2.5” stands for “250”. Heterogeneous Concurrent Modeling and Design 89
Page 1 and 2:
PTOLEMY II HETEROGENEOUS CONCURRENT
Page 3 and 4:
VOLUME 1 INTRODUCTION TO PTOLEMY II
Page 5 and 6:
Volume 1 Contents Introduction to P
Page 7 and 8:
2.10.3. Constructing Modal Models 8
Page 9 and 10:
7. MoML 191 7.1. Introduction 191 7
Page 11 and 12:
1 Introduction Author: Edward A. Le
Page 13 and 14:
Introduction heterochronous dataflo
Page 15 and 16:
Introduction A major emphasis in Pt
Page 17 and 18:
Introduction determine when actors
Page 19 and 20:
Introduction provides levels of vis
Page 21 and 22:
Introduction is a guard, and the se
Page 23 and 24:
Introduction well. All of these are
Page 25 and 26:
Introduction clients to update thei
Page 27 and 28:
Introduction will be supplied with
Page 29 and 30:
Introduction 1.3.12 Synchronous Dat
Page 31 and 32:
Introduction FIGURE 1.10. Refinemen
Page 33 and 34:
Introduction occlusions due to terr
Page 35 and 36:
Introduction tion. The overall arch
Page 37 and 38:
Introduction kernel.attributes This
Page 39 and 40:
Introduction 1.5.2 Overview of Key
Page 41 and 42:
Introduction Actor interfaces are k
Page 43 and 44:
Heterogeneous Concurrent Modeling a
Page 45 and 46:
Introduction actor actor.gui data.e
Page 47 and 48: Introduction cient, scalable, and u
Page 49 and 50: Introduction 1.5.8 Future Capabilit
Page 51 and 52: Introduction Appendix A: UML — Un
Page 53 and 54: Introduction grams, the only constr
Page 55 and 56: 2 Using Vergil Authors: Edward A. L
Page 57 and 58: Using Vergil 2.2.2 Executing a Pre-
Page 59 and 60: Using Vergil The Lorenz attractor m
Page 61 and 62: Using Vergil The Continuous-Time (C
Page 63 and 64: Using Vergil box in figure 2.11. En
Page 65 and 66: Using Vergil Don’t panic! Excepti
Page 67 and 68: Using Vergil tions are a normal par
Page 69 and 70: Using Vergil 2.4 Hierarchy Ptolemy
Page 71 and 72: Using Vergil Then using these ports
Page 73 and 74: Using Vergil the default 0.1 to 0.0
Page 75 and 76: Using Vergil pan window, it is easy
Page 77 and 78: Using Vergil FIGURE 2.33. The pan w
Page 79 and 80: Using Vergil we have modified the c
Page 81 and 82: Using Vergil model, simply copy (or
Page 83 and 84: Using Vergil A key issue is to deci
Page 85 and 86: Using Vergil instances. This proble
Page 87 and 88: Using Vergil quick tour for more de
Page 89 and 90: Using Vergil uses the index in the
Page 91 and 92: Using Vergil AddSubtract actor, and
Page 93 and 94: Using Vergil If you look inside the
Page 95 and 96: Using Vergil If you look inside the
Page 97: Using Vergil transition (or right c
Page 101 and 102: Using Vergil The grid is turned off
Page 103 and 104: Authors: Edward A. Lee Xiaojun Liu
Page 105 and 106: Expressions classes to create a gen
Page 107 and 108: Expressions The % operation is a mo
Page 109 and 110: Expressions attribute, which includ
Page 111 and 112: Expressions 3.3.5 State Machines Ex
Page 113 and 114: Expressions whose value is an array
Page 115 and 116: Expressions from it. For instance,
Page 117 and 118: Expressions defined. For example, >
Page 119 and 120: Expressions length is given by the
Page 121 and 122: Expressions Thus, for example, you
Page 123 and 124: Expressions number. With one additi
Page 125 and 126: Expressions value. For example, fix
Page 127 and 128: Expressions In the example in figur
Page 129 and 130: Expressions A.2 Basic Mathematical
Page 131 and 132: Expressions A.3 Matrix, Array, and
Page 133 and 134: Expressions A.5 Signal Processing F
Page 135 and 136: Expressions TABLE 8: Functions perf
Page 137 and 138: 4 Actor Libraries Authors: Elaine C
Page 139 and 140: Actor Libraries properly in the CT
Page 141 and 142: Actor Libraries ing that multiple c
Page 143 and 144: Actor Libraries TypedAtomicActor «
Page 145 and 146: Actor Libraries SequenceScope (exte
Page 147 and 148: Actor Libraries UnsignedByteArrayTo
Page 149 and 150:
Actor Libraries MobileFunction (ext
Page 151 and 152:
Actor Libraries LogicFunction (exte
Page 153 and 154:
Actor Libraries Sleep (extends Tran
Page 155 and 156:
Actor Libraries VariableFIR (extend
Page 157 and 158:
Actor Libraries Integrator: Integra
Page 159 and 160:
Actor Libraries Figure 4.4 shows th
Page 161 and 162:
5 Designing Actors Authors: Christo
Page 163 and 164:
Designing Actors /** Javadoc commen
Page 165 and 166:
Designing Actors although with most
Page 167 and 168:
Designing Actors import ptolemy.act
Page 169 and 170:
Designing Actors makes such actors
Page 171 and 172:
Designing Actors same parameter val
Page 173 and 174:
Designing Actors morphic actor comp
Page 175 and 176:
Designing Actors To get data polymo
Page 177 and 178:
Designing Actors public class Seque
Page 179 and 180:
Designing Actors be used in domains
Page 181 and 182:
Designing Actors alComm actor. Beca
Page 183 and 184:
Designing Actors attribute has valu
Page 185 and 186:
Designing Actors import ptolemy.act
Page 187 and 188:
6 Coding Style Authors: Christopher
Page 189 and 190:
Coding Style /* One line descriptio
Page 191 and 192:
Coding Style Copyright (c) 2004 The
Page 193 and 194:
Coding Style @version $Id: NamedObj
Page 195 and 196:
Coding Style } We use instead the i
Page 197 and 198:
Coding Style * @exception MyExcepti
Page 199 and 200:
Coding Style + "it does not impleme
Page 201 and 202:
Authors: Edward A. Lee Steve Neuend
Page 203 and 204:
MoML cutes it forever, until you hi
Page 205 and 206:
MoML A second difference between ou
Page 207 and 208:
MoML
Page 209 and 210:
MoML 7.3.3 Names and Classes Most M
Page 211 and 212:
MoML Here, the element named
Page 213 and 214:
MoML implement. 7.3.7 Doc Element S
Page 215 and 216:
MoML It is also sometimes necess
Page 217 and 218:
MoML then there will be a link t
Page 219 and 220:
MoML found. For example, if the cla
Page 221 and 222:
MoML it cannot collide with the nam
Page 223 and 224:
MoML The rendering of the icon is d
Page 225 and 226:
MoML 7.4.5 Deleting Entities, Relat
Page 227 and 228:
MoML This unlinks a port from the s
Page 229 and 230:
MoML model. The EntityLibrary class
Page 231 and 232:
MoML Suppose that using incremental
Page 233 and 234:
MoML Generate a sine wave.
Page 235 and 236:
MoML
Page 237 and 238:
MoML Number of iterations in
Page 239 and 240:
MoML -P- The f
Page 241 and 242:
MoML -P- The phase,
Page 243 and 244:
8 Custom Applets Authors: Edward A.
Page 245 and 246:
Custom Applets html code, see the J
Page 247 and 248:
Custom Applets public class Tutoria
Page 249 and 250:
Custom Applets then the result of
Page 251 and 252:
Custom Applets 8.3.5 Using Model Pa
Page 253 and 254:
Custom Applets ptolemy/domains/doma
Page 255 and 256:
References [1] G. Agha, Actors: A M
Page 257 and 258:
[33] S. A. Edwards, “The Specific
Page 259 and 260:
[67] E. Kohler, The Click Modular R
Page 261 and 262:
[95] J. Liu, X. Liu, T. J. Koo, B.
Page 263 and 264:
[132]W. R. Sutherland, "The on-Line
Page 265 and 266:
Glossary abstract syntax ..........
Page 267 and 268:
Ptolemy II ........................
Page 269 and 270:
Index Symbols - in UML 41 # in UML
Page 271 and 272:
coin flips 142 Color class 173 colo
Page 273 and 274:
entity in XML 198 EntityLibrary cla
Page 275 and 276:
Director class 159 inverse FFT 124
Page 277 and 278:
CompositeEntity class 206 nextPower
Page 279 and 280:
safety 34 SampleDelay actor 78, 138
Page 281 and 282:
type constraint 155 type constraint
show all

PTOLEMY II - CiteSeerX

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?